I know of no speaker designs that can hang with e-stats or planer designs....Why limit your self to these two?
Sophia's are very musical, beautiful to look at, and easy to work with. I feed them with all Krells (KPS-28c, KCT, 400cx). They don't go as deep in bass though - I supplement mine with Rel Stadium III subwoofer and very happy. You can pick up used Pup VI, will go deeper in bass (I would not mess with Pup V) for around $8.5K to $9K.
I find the Sophias more enjoyable to listen to over the long-term than the W/P 6. The 6 still is bright to my ears although does have better bass than the Sophias. The Sophias top to bottom are much more coherant to me too. The 7s are much better in this regard.
fwiw, I think the better jump is from Sophias to Maxxs rather than even 7s.